Ship stabilizing system



' 2 Sheets-Sheet 1 Filed June 4. 1968 Hqrsf Jurgen BY W flffO/"n April7, 1970 HALDEN ET AL SHIP STABILIZING SYSTEM 2 Sheets-Sheet 2 Filed June4. 1968 Fig.3a

. h v J Q Q Q w a b 3 a G F x f 5 0 3 I ,iL L 3 a h 0 n t e n 0% w F E Hw 4m M m HJ United States Patent O 3,504,651 SHIP STABILIZING SYSTEMHorst Halden, Hamburg, and Jiirgen Fehlauer, Wolfsburg,

Germany, assignors to Licentia Patent-Verwaltuugs- G.m.b.H., Frankfurtam Main, Germany Filed June 4, 1968, Ser. No. 734,410 Int. Cl. B63b43/06 U.S. Cl. 114-125 8 Claims ABSTRACT OF THE DISCLOSURE A system forstabilizing ships of the type having a liquid storage tank with firstand second portions, in fluid com munication with each other, located onopposite sides of a ship. The level of the liquid in the tank can bechanged quickly, this being done with means which communicate with thetank for introducing a pressure medium into the tank at a point belowthe surface of the liquid in the tank and with two separately closableoutlet means communicating with the respective tank portions forallowing the liquid and/or the air in one or the other or both the tankportions to escape.

BACKGROUND OF THE INVENTION The present invention relates to apparatusfor quickly changing the level of liquid in the liquid tank or tanks ofa ship stabilizing system.

When a ship having a liquid tank-type stabilizing system has beendamaged at sea, the danger to the ship can be additionally increased bythe freely oscillating or rolling masses of liquid in the tank system.It is necessary that these oscillations be braked and that the liquid bedistri'buted uniformly throughout the ships tanks in the shortestpossible time (e.g., 20 seconds) or that the tank system be quicklyemptied,

With air pressure-activated tank-type stabilizing systems it is known inthe art to change the characteristics frequency of the liquid in theanti-rolling tanks by inserting an air compressor in the air lineinterconnecting the side tanks. Such an air compression is slow tooperate, however, and is not effective in emptying the tanks.

SUMMARY OF THE INVENTION An object of the present invention, therefore,is to provide apparatus for suppressing, when necessary, theoscillations of the liquid in-or for emptying the liquid fromthe tanksystem of a tank-type ship stabilizing system, in the shortest possibletime. The term tank system, as used here, is intended to include a tankhaving first and second portions located on opposite sides of the shipand in fluid communication with each other.

This, as well as other objects which will become apparent in thediscussion that follows, is achieved, according to the presentinvention, by providing means communicating with the tank system, meansfor introducing a pres sure medium below the surface of a liquid storedin the tank system and separately closable first and second outletscommunicating with the first and second tank portions, respectively. Byintroducing the pressure medium into the tank system it is possible tocause the liquid in at least one of the tank portions to be underpressure. This pressure can then be relieved by allowing the liquid and/or air in one or the other or both tank portions to escape.

A gas is used as a pressure medium, according to the present invention.This gas may either be introduced into the tank system under pressure orpassed through the tank inlet openings in the liquid state and allowedto boil.

It would be conceivable to construct the means communicating with thetank system so that it introduces the Patented Apr. 7, 1970 pressuremediume.g., a gas under pressureat a point above the level of theliquid. However, the cooling which results from the expansion of the gasin the tank space would make it diflicult to introduce the necessaryquantity of gas in the prescribed time. Unless a costly preheatingapparatus were provided, at least part of the pressure medium wouldfreeze.

The cooling of the gas to this undesirable degree will be avoided byintroducing the gas directly into the tank liquid. The flow of the gasthrough the liquid will then result in a heat exchange that will besufiicient to insure that the gas will not freeze.

If the ship stabiilzing system is of the type having side tanks with atleast one liquid equalizing channel and at least one closable airequalizing channel interconnecting the tanks, a preferred embodiment ofthe present inven tion provides that the inlet openings for the gasunder pressure are arranged either in the lower half of the side tanksor at the ends of the liquid equalizing channels. The separatelyclosable outlets which permit compressed air to escape from the tanksare likewise arranged in the upper half of the tanks or at the ends ofthe air equalizing channels. If the liquid located in the side tanks ofthis stabilizing system is then caused to flow into one of the sidetanks, it can be forced back again into the other side tank by closingthe air equalizing channel in an air tight manner and opening theseparately closable outlet of the tank to be filled so that the air,which is displaced by the liquid, is allowed to escape.

If the ship is damaged at sea it can be of advantage if the liquid inthe tanks of the ship stabilizing system can be jettisoned in theshortest possible time. Thus, ac cording to a further embodiment of thepresent invention, each side tank is provided, near its bottom, with anoutlet opening for the liquid. The gas is then introduced underpressure, with the air equalizing channel open and the outlet openingslocated in the upper half of the side tanks closed, and the liquid isdisplaced by the gas.

With a. ship stabilizing system having a tank constructed to operateaccording to the fiume principle it is again desirable that the liquidbe jettisoned from the tank when the ship has been damaged. With asystem of this type in which the tank liquid oscillates back and forthin a direction transverse to the forward motion of the ship in a tankconsisting of a number of containers of various cross sections, it isnot possible, by introducing a gas under pressure, to dampen theoscillations or change the respective levels of the fiuid since thepressure of the gas will uniformly act upon the entire surface of thetank liquid.

The apparatus according to the present invention for controlling theliquid level or to jettison the liquid in the tank of a ship stabilizingsystem may also be used for other known types of ship stabilizingsystems. For example, it may be used in active ship stabilizing systems.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a schematic diagram of thesection of a ship having a stabilizing system with a U-shaped tank,according to a preferred embodiment of the present invention.

FIGURE 2 is a schematic diagram of a section of a ship having astabilizing system with a U-shaped tank, according to another preferredembodiment of the present invention.

FIGURE 3a is a schematic diagram of a section of a ship having astabilizing system, according to still another preferred embodiment ofthe present invention, which system has a tank arranged to operateaccording to the flume principle.

FIGURE 3b is a schematic diagram, in top view, of the ship stabilizingsystem of FIGURE 3a.

3 DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to thedrawings, FIGURE 1 illustrates schematically a passive ship stabilizingsystem having two side tanks and 11 which are joined together by aninterconnecting channel 12 and a pressure equalizing air line 13. A flapor butterfly valve which is driven by a position adjusting device 14 isarranged in the air line 13.

This valve 15 may be closed to completely seal the air passagewaybetween the side tanks 10 and 11.

A container 16 which holds under pressure a pressure medium either inthe gaseous or liquid state is connected to the side tanks 10 and 11through the lines 17 and the throttle valves 18 and 19. Arranged in theair line 13 on both sides of the flap 15 are openings 22 and 23 whichmay be independently closed by valves and 21, respectively. Highpressure release valves 24 and 25 are also connected to the air line.Float apparatus 26 and 27 is provided in each side tank 10 and 11,respectively, for measuring the level of the liquid in the tanks.

It is particularly practical if the gas which is to be inserted in theside tanks 10 and 11 is stored in the container 16 and introduced intothe tanks in the liquid state.

It is possible, for the purposes of the present invention, to use anygas which is not explosive, corrosive, or poisonous. If the gas is to bestored in the liquid state, however, it is preferable to choose a gasthat has a boiling point only slightly below room temperature. Thispermits the gas to be stored without the requirement of costly coolingapparatus.

According to a preferred embodiment of the present invention afiuorinated hydrocarbon gas is stored and introduced into the side tanksin its liquid state. Dichlorodifluoromethane has proven especiallyadvantageous in this regard. Its boiling point lies approximately at C.It is not poisonous, corrosive or explosive and it exhibits but alimited solubility in water.

If the ship having a stabilizing system of the type shown in FIGURE 1 isdamaged and continually lists toward one side, most of the tank liquidwill flow into the tank on the lower side of the ship and cause the shipto list still further. If it is assumed, for purposes of example, thatthe ship is listing toward the right, the valve 19 will open, after analarm signal is sounded, and allow the liquid dichlorodifiuoromethanewhich is stored under pressure in the container 16 to escape into thetank liquid of the side tank 11. The flap 15 in the pressure equalizingair channel 13 will simultaneously close. The liquid gas will thenexpand and press down from above on the column of liquid in the sidetank 11. This will force a portion of this liquid back into the otherside tank 10 and thus raise the level of liquid in this left tank. Theair in the side tank 10 which is displaced by the incoming liquid can beallowed to escape by opening the valve 20 while all the other valves areheld closed. The amount of gas which is permitted to flow into the sidetank 11 may be chosen so that the liquid in both tanks 10 and 11 willreach a desired level.

Since the gas is introduced into the tank liquid in the liquid state aheat exchange will occur between the incoming expanding gas and the tankliquid. The heat which is given to the gas by the liquid is sufficientto prevent the gas from freezing even during the strong expansion whichis necessary here to introduce the desired quantity of gas into thetank. If the gas were introduced into the side tank 11 above the levelof the liquid, the danger of freezing would make diflicult theintroduction of the necessary quantity of gas in a short time.

' In order to eliminate the disadvantages of a tank-type shipstabilizing system when the ship is damaged at sea, it may also bedesirable to quickly jettison the stabilizing liquid from the tanks.This can also be accomplished with the aid of the apparatus according tothe present invention by introducing the gas into the tank space belowthe level .4 of the liquid and allowing the liquid to escape throughside openings in the tank.

The apparatus necessary to jettison the liquid in the tanks isschematically shown in FIGURE 2. This figure illustrates a passivestabilizing system of the type shown in FIGURE 1 which also includesside tanks 10 and 11, an interconnecting channel 12 and an air line 13.The means for introducing the gas into the tanks 10 and 11 includes,again, the container 16, the lines 17 and the throttle valves 18 and 19.The lines 17 and the valves 18 and 19 are arranged to introduce the gasat a point in the tanks which is lower than the point at which the gaswas introduced by the corresponding lines and valves of FIGURE 1. Thetanks 10 and 11 are provided with flap openings 28 and 29, respectively,through which the liquid may be expelled. As the gas from the container16 is introduced into the tanks 10 and 11, it rises to the air space Iabove the level of the liquid and forces the liquid out.

FIGURES 3a and 3b illustrate another embodiment of the present inventionas applied to a ship stabilizing system 30 which operates according tothe flume" principle. The purpose of this embodiment is to jettison theliquid stored in the system 30 as quickly as possible. It is notpossible, with a system of this type, to change the relative levels ofthe liquid at various points of the system.

The gas is again stored, under pressure, in a container 31 in either theliquid or the gaseous state. This gas is passed through lines 32 and 33and through valves 34 and 35 into the tank space at points below thelevel of the liquid. When introduced, this gas will rise to the top ofthe tank space and press the liquid out through flaps 36 and 37.

It will be understood that the above description of the presentinvention is susceptible to various modifications, changes, andadaptations.

We claim:

1. A ship stablizing system comprising, in combination:

(a) tank means having first and second portions located on oppositesides of the ship, respectively, said portions being in fluidcommunication with each other for passing fluid therebetween;

(b) means communicating with said tank means for introducing a liquidpressure medium which is a gas at room temperature and atmosphericpressure below the surface of a liquid in said tank means and therebycausing the liquid in at least one of said portions to be underpressure;

(c) separately olosable first and second outlet means communicating withsaid first and second tank portions, respectively.

2. The system defined in claim 1, wherein said first and second outletmeans communicate with the bottoms of said first and second tankportions.

3. The system defined in claim 1 wherein said pressure medium is afi-uorinated hydrocarbon gas.

4. The system defined in claim 3, wherein said pressure medium isdichlorodifluoromethane.

5. A ship stabilizing system comprising in combination:

(a) tank means having first and second portions located on oppositesides of the ship, respectively, said portions being in fluidcommunication with each other for passing fluid therebetween;

(b) means communicating with said tank means for introducing a pressuremedium below the surface of a liquid in said tank means and therebycausing the liquid in at least one of said portions to be underpressure.

(c) separately closable first and second outlet means communicating withsaid and second tank portions, respectively, and

(d) said first and outlet means communicating with the tops of saidfirst and second tank portions, and

(c) said tank means including at least one liquid equalizing channelinterconnecting said first and said second portions below the level ofsaid liquid, at least one air equalizing channel interconnecting saidfirst and said second portions above the level of said liquid and meansfor closing said at least one air equalizing channel.

6. The system defined in claim 5, wherein said introducing meansintroduces said pressure medium into said tank means at the ends of saidat least one liquid equalizing channel.

7. The system defined in claim 5, wherein said first and second outletmeans are arranged at the ends of said at least one air equalizingchannel.

8. The system as defined in claim 1 including storage means for holdingsaid liquid pressure medium under pressure in the liquid condition, anda pressure medium stored in said storage means which is a gas at roomtemperature and atmospheric pressure and a liquid at the pressuremaintained in the storage means.

References Cited UNITED STATES PATENTS 1,888,667 11/1932 Hort l14125FOREIGN PATENTS 645,660 6/1937 Germany.

OTHER REFERENCES Ser. No. 132,695, Hort (A.P.C.), published May 11,1943.

TRYGVE M. BLIX, Primary Examiner

